Digital still cameras capable of capturing video have become widespread in recent years. While the resolution and image quality of these consumer devices has improved up to the point where they rival digital single-lens reflex cameras (DSLRs) in some settings, their video quality may still be significantly worse than that of film cameras. The reason for this gap in quality may be twofold. First, compared to film cameras, cell phones may be significantly lighter. As a result, hand-held video capture on such devices may exhibit a greater amount of camera shake. Second, cell-phone cameras may have sensors that make use of a rolling shutter (RS). In an RS camera, each image row may be exposed at a slightly different time, which, combined with undampened camera motion, may result in a “wobble” in the output video.
Video stabilization is a family of techniques used to reduce high-frequency frame-to-frame jitter produced by video camera shake. In professional cameras, mechanical image stabilization (MIS) systems are commonly used. For example, in an MIS system, the operator may wear a harness that separates the camera's motion from the operator's body motion. Other MIS systems stabilize the optics of the camera rather than the camera body itself. These systems may move the lens or sensor to compensate for small pitch and yaw motions. These techniques work in real time and do not require computation on the camera. However, they are not suitable for mobile devices and inexpensive cameras, because of their price and size. Digital video stabilization systems may employ feature trackers to stabilize videos post-capture. However, these systems may be sensitive to noise (e.g., fast moving foreground objects) and require distinctive features for tracking. As a result, digital stabilization based on feature tracking often breaks down, especially in adverse lighting conditions and excessive foreground motion. In addition, extracting and matching visual cues across frames can be computationally expensive. Furthermore, the expense grows with the resolution of the video. In some instances, this may be too costly to perform video stabilization in real time. Consequently, such approaches are rarely employed in current digital cameras. Instead, manufacturers can opt for more robust (and expensive) mechanical stabilization solutions for high-end DSLRs.